Process for producing trihydrocarbyl aluminums

ABSTRACT

A trihydrocarbyl aluminum is produced at a high yield by reacting an aluminum-magnesium alloy powder with a halogenated hydrocarbon. Prior to the reaction, the alloy powder is obtained by grinding treatment using a ball mill or a vibration ball mill. The reaction is conducted with agitation in the presence of abrasive particles or is conducted using a homogenizer without abrasive particles.

This is a 35 USC §371 application of PCT/JP98/03217.

TECHNICAL FIELD PERTINENT TO THE INVENTION

The present invention relates to a process for producing atrihydrocarbyl aluminum which is an important co-catalyst for olefinpolymerization.

PRIOR ART

The process for synthesizing a trialkyl aluminum from analuminum-magnesium alloy and a halogenated alkyl is known and isdescribed in, for example, U.S. Pat. No. 2,744,127 of K. Ziegler.

In this U.S. Patent use of an aluminum-magnesium alloy composed of 35 to43% aluminum and 57 to 65% magnesium is described. It is also describedthat trimethyl aluminum can be synthesized at a yield of 60 to 75% frommethyl bromide and the above aluminum-magnesium alloy. The literature,however, makes no mention of whether or not trimethyl aluminum can besynthesized from methyl chloride and an aluminum-magnesium alloy.

It is also described that triethyl aluminum can be synthesized fromethyl bromide and an aluminum-magnesium alloy at a yield of 75 to 85%.The literature gives an Example wherein triethyl aluminum can besynthesized from ethyl chloride and an aluminum-magnesium alloy, butmakes no mention on the yield.

In the synthesis of trimethyl aluminum, there has been an industriallyand economically serious drawback in that particularly when methylchloride of low cost and easy availability is used in volume, thereaction does no proceed favorably.

The primary object of the present invention is to provide a processwhich can produce trimethyl aluminum using methyl chloride of low costand easy availability in volume, at a yield at least equal to thatobtained using iodide or bromide.

Another object of the present invention is to provide a process whereinthe reaction proceeds easily and the yield is high when compared withconventional processes, even when an iodinated hydrocarbon or abrominated hydrocarbon is used as a raw material.

MEANS FOR ACHIEVING THE TASK

The present inventors conducted a study in order to solve the aboveproblems and, as a result, have completed the present invention. Thepresent invention comprises the following invention and embodiments.

(1) A process for producing a trihydrocarbyl aluminum by reacting analuminum-magnesium alloy containing 20 to 80% by weight aluminum and 80to 20% by weight magnesium, with a halogenated hydrocarbon, in whichprocess

the aluminum-magnesium alloy has been subjected to a grinding treatmentin the presence of an abrasive medium by the use of a ball mill or avibration ball mill, and/or,

in the reaction, agitation is conducted in the presence of an abrasivemedium or there is used a homogenizer rotating at a high speed of 5,000to 20,000 rpm.

(2) A process for producing a trihydrocarbyl aluminum by reacting analuminum-magnesium alloy with a halogenated hydrocarbon according to theabove (1), in which process,

in the reaction, agitation is conducted in the presence of an abrasivemedium.

(3) A process for producing a trihydrocarbyl aluminum by reacting analuminum-magnesium alloy with a halogenated hydrocarbon according to theabove (1), in which process,

in the reaction, there is used a homogenizer rotating at a high speed of5,000 to 20,000 rpm.

(4) A process for producing a trihydrocarbyl aluminum by reacting analuminum-magnesium alloy with a halogenated hydrocarbon according to theabove (1), in which process

the aluminum-magnesium alloy has been subjected to a grinding treatmentin the presence of an abrasive medium by the use of a ball mill orvibration ball mill, and

in the reaction, agitation is conducted in the presence of an abrasivemedium.

(5) A process for producing a trihydrocarbyl aluminum according to anyof the above (1) to (4), wherein the aluminum-magnesium alloy contains35 to 45% by weight of aluminum and 55 to 65% by weight of magnesium.

(6) A process for producing a trihydrocarbyl aluminum according to anyof the above (1) to (5), wherein the halogenated hydrocarbon is used inan amount of 2.0 to 10.0 moles per mole of the aluminum in thealuminum-magnesium alloy.

(7) A process for producing a trihydrocarbyl aluminum according to anyof the above (1) to (6), wherein the halogenated hydrocarbon is a methylhalide.

(8) A process for producing a trihydrocarbyl aluminum according to theabove (7), wherein the halogenated hydrocarbon is methyl chloride.

MODE FOR CARRYING OUT THE INVENTION

The present invention is hereinafter described in more detail.

The reaction of the present invention is represented by the followingreaction formula when the aluminum-magnesium alloy used is Al₂Mg₃.

Al₂Mg₃+6RX→2AlR₃+3MgX₂  (1)

In the above formula, R is a chain or cyclic hydrocarbon residue having1 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms, andspecific examples thereof are methyl group, ethyl group, n-propyl group,isopropyl group, n-butyl group, isobutyl group, sec-butyl group, n-hexylgroup, n-octyl group, cyclohexyl group, phenyl group and benzyl group; Xis chlorine, bromine or iodine.

In the present invention, particularly remarkable effects can beobtained when RX is methyl chloride.

In the aluminum-magnesium alloy used in the reaction, the atomiccomposition is such that the aluminum content is 20 to 80% by weight,preferably 30 to 60% by weight, particularly preferably 35 to 45% byweight and the magnesium content is 80 to 20% by weight, preferably 40to 70% by weight, particularly preferably 55 to 65% by weight.

There is no particular restriction as to the atomic composition of thealuminum-magnesium alloy as long as the composition is in the aboverange.

However, an atomic composition consisting of 35 to 45% by weight ofaluminum and 55 to 65% by weight magnesium is particularly preferred.

The aluminum-magnesium alloy having the above atomic composition ispreferred because the amounts of the two components in the alloy areclose to stoichiometric amounts and moreover the alloy is very brittleand can be easily made into a fine powder by the grinding treatmentdescribed later. Since the aluminum-magnesium alloy of the above atomiccomposition, i.e. a composition close to Al₂Mg₃ leaves little reside inthe reaction and is preferred economically and industrially, the mostpreferred atomic composition is a composition close to Al₂Mg₃ (Al: 42.6%by weight, Mg: 57.4% by weight). When a commercially available alloy isout of this compositional range, magnesium or aluminum is added theretoand, as necessary, grinding is conducted, whereby a particularlypreferred compositional range can be obtained.

It is generally known that aluminum-magnesium alloy consists of variouskinds of crystals, each of which is different in atomic composition. Inorder to carry out the reaction smoothly, it is preferable that thealuminum-magnesium alloy used in the present invention be as uniform aspossible in crystal structure and atomic composition throughout thealloy portion. Moreover, it is desirable that the crystal structure beas amorphous as possible.

An aluminum-magnesium alloy uniform in crystal structure and in atomiccomposition throughout the alloy portion, such as mentioned above, canbe obtained by melting aluminum and magnesium and then cooling the meltrapidly.

As a method for rapidly cooling the melt of aluminum and magnesium,there can be employed, for example, a well-known method used inproduction of amorphous alloy, such as the atomization method, liquidrapid cooling method or the like.

The above-mentioned aluminum-magnesium alloy is used in the state of afine powder. When the fine powder is obtained by a grinding treatment inthe presence of an abrasive medium by the use of a ball mill or avibration ball mill (Vibratom), a good result can be obtained. However,the present invention process is applicable also to a case of using afine powder of aluminum-magnesium alloy produced by the knownatomization or stamp mill method.

Grinding by ball mill is conducted by feeding an abrasive medium (balls)and a material to be ground, into a container and grinding the materialto be ground, into a fine powder by collision with moving balls. It isgenerally carried out by rotating the container by an external force,but may be carried out in other ways.

Grinding by vibration ball mill is a kind of the above mentionedgrinding by ball mill, and is conducted by feeding an abrasive medium(balls) and a material to be ground, into a container and vibrating thecontainer vigorously vertically and horizontally by an external force togrind the material to be ground, into a fine powder by collision withmoving balls. In the present invention, use of, in particular, avibration ball mill is recommended in view of the grinding efficiency.

There is no particular restriction as to the kind of the abrasive mediumused. However, the abrasive medium can be exemplified by balls made of ametal such as iron, stainless steel or the like; and balls made of aceramic (e.g. silica or alumina), glass, agate or the like. There is noparticular restriction as to the size of the abrasive medium; however,the size is appropriately a sphere of about 0.2 to 3 cm in diameter. Theamount of the abrasive medium used can be appropriately determineddepending upon the amount of the aluminum-magnesium alloy to be ground;however, it is generally about 2 to 30 times the weight of thealuminum-magnesium alloy used. A very small amount of a grinding aidsuch as stearic acid or the like may be used to improve the efficiencyof grinding.

The grinding time varies depending upon the amount of the material to beground, the amount and shape of the abrasive material and the operatingconditions of the grinding apparatus; however, it is generally about 5minutes to 96 hours and, when a vibration ball mill is used, is about 5minutes to 24 hours.

The halogenated hydrocarbon used in the process of the present inventioncan be one of ordinary availability, but is preferably free from oxygenor water.

The halogenated hydrocarbon used in the present invention is representedby the general formula RX. In the formula, R is a saturated orunsaturated chain or cyclic hydrocarbon residue having 1 to 20 carbonatoms, or an aryl group having 6 to 20 carbon atoms. Specific examplesof R are methyl group, ethyl group, n-propyl group, isopropyl group,n-butyl group, isobutyl group, sec-butyl group, n-hexyl group, n-octylgroup, cyclohexyl group, phenyl group and benzyl group. X is chlorine,bromine or iodine.

The effects of the present invention are exhibited clearly when thehalogenated hydrocarbon is methyl chloride.

The present inventors conducted a study on the reactivity when theabove-mentioned aluminum-magnesium alloy was suspended in a reactionsolvent in a reaction vessel and, while the suspension was agitated,methyl chloride as halogenated hydrocarbon was added. However, the yieldwas unexpectedly low.

As a result of a further study, it was found out that when the agitationwas conducted in the presence of an abrasive medium, the yield increasedto 5 times or more. The finding led to the completion of the presentinvention.

As the reactor used in the reaction, a vertical or horizontalpressure-resistant reactor is used. For example, an autoclave equippedwith an agitator is used. The blade used therein can be any is bladewhich is generally known, such as propeller, turbine, Pfaudler type,Maxblend type, full zone type or the like. Agitation is conducted in thepresence of an abrasive medium, which is a feature of the presentinvention.

The abrasive medium consists of nearly spherical particles made of aglass, silica, a ceramic (e.g. alumina), agate, a metal (e.g. iron orSUS) or the like. These particles are moved and caused to collide witheach other by the agitation of the agitator blades, whereby they cangrind the solid contained in the reaction mixture.

The size of the abrasive medium is generally about 0.5 to 10 mm,preferably 2 to 5 mm, in diameter.

The amount of the abrasive medium fed differs depending upon chemicalfactors such as concentrations and viscosities of reagents contained inreaction mixture, and the like and engineering factors such as size ofthe reaction vessel, size and shape of the blade, and the like; however,it is preferably 10 to 50% by weight of the total weight of the reactionmixture.

The effects of the abrasive medium of the present invention aredescribed in detail. It is presumed that by conducting agitation in thepresence of an abrasive medium in the reaction betweenaluminum-magnesium alloy and methyl chloride, the magnesium chloride(which is formed as a by-product in the reaction and adheres strongly onthe surface of the solid aluminum-magnesium alloy) is rubbed off and thesurface is always kept fresh; as a result, the reaction between solidaluminum-magnesium alloy and methyl chloride dissolved in solvent canproceed smoothly without being interrupted by the by-product; thereby,trimethyl aluminum can be obtained stably at a high yield.

It is also presumed that the aluminum-magnesium alloy is ground into afiner state in the course of the reaction by collision with the abrasivemedium particles; the surface area of the alloy participating in thereaction becomes larger; thereby, the reaction speed becomes faster; andtrimethyl aluminum can be obtained at a higher yield.

In the reaction of the present invention, it is possible to use ahomogenizer rotating at a high speed of 5,000 to 20,000 rpm, wherebysuperior effects can be obtained as compared with the case of a reactionusing ordinary agitation.

The above homogenizer is one ordinarily called “homogenizer” in therelated field. It is an apparatus for giving rise to agitation andemulsification by the utilization of the impact and eddy current causedby the blades rotating at a high speed. It can use blades rotating at ahigh speed only, or can combine the blades with stationary blades. It isalso possible to use the homogenizer described on page 440 of “ShinpanKagaku Kogyo Jiten” (published by Maruzen Co.).

In the present process, the speed of agitation employed in the reactionbetween the aluminum-magnesium alloy and the halogenated hydrocarbon isdetermined by the size of reaction vessel, the amount of abrasivemedium, the amounts of reagents and solvent, etc. However, the agitationspeed can ordinarily be 50 to 5,000 rpm.

The amount of halogenated hydrocarbon used can be 2 quivalents or morerelative to the aluminum in the aluminum-magnesium alloy. Use of thehalogenated hydrocarbon preferably in an amount of 3 equivalents(theoretical amount as seen in the formula (1)) or more, more preferablyin an excessive amount relative to aluminum, can give a good yield. Usein an amount of 3.5 equivalents or more, most preferably in an amount of4 equivalents or more, is recommendable to obtain a high yield. There isno particular restriction as to the upper limit of the amount of thehalogenated hydrocarbon; however, use of the halogenated hydrocarbon inan amount of about 10 equivalents relative to aluminum is sufficient.

The reaction is conducted by adding the halogenated hydrocarbon to thealuminum-magnesium alloy. The addition may be continuous orintermittent.

It is also possible to mix beforehand the aluminum-magnesium alloy withpart of the halogenated hydrocarbon in a reaction vessel and, after thereaction has been started, add the remainder of the halogenatedhydrocarbon. It is also possible to add, as a reaction initiator toshorten the induction period of the reaction and start the reactionquickly, a small amount of an alkyl aluminum halide (e.g. alkyl aluminumsesquichloride, dialkyl aluminum chloride or alkyl aluminum dichloride),iodine, aluminum bromide or the like.

In the reaction, a solvent may be used. As the solvent, there can bementioned, for example, aromatic hydrocarbons such as benzene, toluene,xylene and the like; and aliphatic hydrocarbons such as hexane, heptane,octane, liquid paraffin and the like.

An ether compound can also be used. However, the ether compound forms acoordination compound with the alkyl aluminum formed and it is difficultto separate the ether compound from the alkyl aluminum.

The reaction is exothermic. When the halogenated hydrocarbon is fedintermittently, agitation is continued from the completion of thefeeding to the completion of the reaction. When the halogenatedhydrocarbon is fed continuously, the feeding rate is controlled toprevent an excessive temperature increase of the reaction system causedby heat generation.

The reaction temperature is about 20 to 170° C., preferably about 30 to150° C., particularly preferably about 80 to 125° C. The reaction timeis about 1 to 48 hours.

In a preferred embodiment of the present invention, analuminum-magnesium alloy containing 35 to 45% by weight aluminum and 55to 65% by weight magnesium is reacted with a halogenated hydrocarbonwith agitation to obtain a trihydrocarbyl aluminum, wherein theagitation is conducted in the presence of an abrasive medium (the use ofthis abrasive medium is a feature of the present invention).

There are conventional processes for obtaining a trialkyl aluminum froman aluminum-magnesium alloy and a halogenated alkyl. However, theprocess of the present invention for synthesizing a trihydrocarbylaluminum from an aluminum-magnesium alloy and a halogenated hydrocarbonunder particular conditions, has not been known.

The present inventors fount that when an aluminum-magnesium alloycontaining 20 to 80% by weight aluminum and 80 to 20% by weightmagnesium is reacted with a halogenated hydrocarbon in a solvent withagitation (the agitation is conducted preferably in the presence of anabrasive medium), the reaction speed increases and an intendedtrihydrocarbyl aluminum can be obtained in a short period of time and ata high yield. The present invention has been completed based on thisfinding.

After the completion of the reaction, a solid composed mainly ofmagnesium chloride (a by-product) and unreacted solid reagent areseparated from the reaction mixture containing the trihydrocarbylaluminum formed. The solid-removed reaction mixture is subjected todistillation or simply to solvent removal, whereby a product isrecovered. However, this initial product right after the above stepcontains a slight amount of a chloride; therefore, it is preferable thatthe initial product be subjected to a dechlorination reaction at atemperature of 80 to 170° C., preferably 80 to 125° C. using adechlorinating agent such as aluminum-magnesium alloy, metallicmagnesium, metallic sodium or the like, to remove the chlorine componentfrom the initial product.

Embodiments

The present invention is described more specifically below by way ofExamples. However, the scope of the present invention is not restrictedby them.

EXAMPLE 1

Metallic aluminum and metallic magnesium were melt and mixed. The moltenmixture was rapidly cooled and solidified to produce analuminum-magnesium alloy having a composition consisting of 42.4% byweight aluminum and 57.6% by weight magnesium. Subsequently, 200SUS-made balls each having a diameter of 1.5 cm where charged into anSUS-made cylindrical container having an internal volume of 2 liters.Thereoto was fed 150 g of the above-produced aluminum-magnesium alloyafter having been ground to a size of about 2 mm×2 mm. The SUS-madecylindrical container was rotated for about 48 hours to grind thealuminum-magnesium alloy.

Thereafter, the ground aluminum-magnesium alloy was separated from theSUS-made balls and sifted through a screen to collect the portion in therange of 75 to 250 μm in diameter as an alloy fine powder.

A 2-liter autoclave was equipped with an agitator and a methyl chloridefeeder, and the inside of the autoclave was purged with nitrogen. Intothe autoclave were fed 45 g of the alloy fine powder obtained by theabove grinding treatment using a ball mill (45 g consisted of 0.677 moleof aluminum and 1.099 moles of magnesium) and 170 ml of n-hexanetogether with 40 g of glass beads of about 3.5 mm in diameter. There wasfurther added methyl aluminum sesquichloride as a reaction initiator.Then, agitation was conducted at room temperature for 3 hours.

Next, methyl chloride was fed into the autoclave while being metered bya transfer pump, to increase the pressure inside the autoclave to 10kg/cm². Then, while the temperature inside the autoclave was kept at120° C., 134 g (2.66 moles, 4.0 equivalents relative to aluminum) ofmethyl chloride was fed to conduct a reaction. The pressure increasedfrom the initial level of 10 kg/cm² to 36 kg/cm².

The time required for the feeding of methyl chloride was 4.2 hours.After the completion of the feeding, the resulting mixture was agitatedfor further 4 hours. The speed of agitation was 700 rpm during thereaction.

The suspension containing a solid composed mainly of magnesium chloride(a by-product) was filtered to remove the solid to obtain a colorlesstransparent crude trimethyl aluminum/hexane solution.

The solution was subjected to distillation to remove the hexane toobtain crude trimethyl aluminum as a distillation residue. The crudetrimethyl aluminum was quantitatively analyzed for aluminum content andchlorine content.

The aluminum content in the crude trimethyl aluminum, other than that inmethyl aluminum sesquichloride was 0.559 mole. This value was 82.6%(crude yield) relative to the aluminum content in the aluminum-magnesiumalloy used originally.

The chlorine content in the crude trimethyl aluminum, including that inmethyl aluminum sesquichloride was 0.327 mole.

To remove the chlorine content from crude trimethyl aluminum, 20.7 g ofthe above-mentioned aluminum-magnesium alloy fine powder (20.7 gconsisting of 0.325 mole of aluminum and 0.491 mole of magnesium) wasadded to the crude trimethyl aluminum; and the resulting mixture wasagitated in the presence of glass beads of about 3.5 mm in diameter at120° C. for 24 hours.

The mixture after agitation was analyzed for chlorine content. Thechlorine content in the mixture was substantially zero.

Then, the mixture was subjected to distillation to obtain trimethylaluminum. The yield of trimethyl aluminum was 65.9% relative to thealuminum in the aluminum-magnesium alloy used originally.

EXAMPLE 2

The aluminum-magnesium alloy obtained in the same manner as in Example 1was ground by using a Vibratom mill (a vibration mill produced byKawasaki Heavy Industries. Ltd.) in place of the ball mill used inExample 1. The portion in the range of 75 to 250 μm in diameter wasseparated out and obtained as an alloy fine powder.

The alloy fine powder was subjected to the same reaction as in Example 1to obtain crude trimethyl aluminum at a yield of 84.5%. The crudetrimethyl aluminum was subjected to distillation to obtain trimethylaluminum at a yield of 67.9%.

EXAMPLE 3

A reaction was conducted in the same manner as in Example 1 except thatthe amount of methyl chloride used was increased to 4.5 equivalentsrelative to aluminum, whereby crude trimethyl aluminum was obtained at ayield (crude yield) of 88.5% and, after distillation, trimethyl aluminumwas obtained at a yield of 70.3%.

EXAMPLE 4

A reaction was conducted in the same manner as in Example 2 except thatthe amount of methyl chloride used was increased to 4.5 equivalentsrelative to aluminum, whereby crude trimethyl aluminum was obtained at ayield (crude yield) of 90.1% and, after distillation, trimethyl aluminumwas obtained at a yield of 72.1%.

EXAMPLE 5

A reaction was conducted in the same manner as in Example 1 except thatthe amount of methyl chloride used was increased to 3.5 equivalentsrelative to aluminum.

Crude trimethyl aluminum was obtained in the same manner as in Example1.

The aluminum content in crude trimethyl aluminum, other than that inmethyl aluminum sesquichloride was 0.494 mole. This value was 73.0%(crude yield) relative to the aluminum content in the aluminum-magnesiumalloy used originally.

The crude trimethyl aluminum was subjected to a dechlorination reactionusing aluminum-magnesium alloy, in the same manner as in Example 1. Toremove a very small amount of chlorine still remaining in the reactionmixture, metallic sodium in an amount in excess of the chlorine wasadded to the reaction mixture, and a reaction was allowed to take placeto remove the chlorine in the liquid layer. The resulting reactionmixture was subjected to distillation to remove n-hexane. Thedistillation residue was subjected to distillation to obtain trime5thylaluminum. The yield thereof was 56% relative to the aluminum in thealuminum-magnesium alloy used originally.

Comparative Example 1

A molten aluminum-magnesium alloy was sprayed in a nitrogen atmosphereby the use of spray dryer, to form fine particles, and the fineparticles were collected using a cooled filter to produce analuminum-magnesium alloy fine powder having the same composition as inExample 1, consisting of 42.4% by weight aluminum and 57.6% by weightmagnesium. The fine powder was sieved through a screen to obtain theportion in the range of 75 to 250 μm in particle diameter.

The above-obtained alloy was subjected to a reaction with methylchloride in the same manner as in Example 1, with the exception thatonly ordinary agitation was conducted in the reaction; no glass beadswere added. Glass beads were used only in the removal of chlorinepresent in the obtained trimethyl aluminum.

In the above reaction between aluminum-magnesium alloy [45 g (0.677 moleas aluminum)] and methyl chloride [134 g (2.66 moles, 4.0 equivalentsrelative to aluminum)], the after-purification yield of trimethylaluminum was 15% (relative to aluminum).

EXAMPLE 6

A reaction was conducted in the same manner as in Example 1, using thesame aluminum-magnesium alloy as used in Example 1 with the exceptionthat, in the reaction of the alloy with methyl chloride, only ordinaryagitation was conducted without glass beads. Glass beads were used onlyin the removal of chlorine present in formed trimethyl aluminum.

In the above reaction between aluminum-magnesium alloy [45 g (0.677 moleas aluminum)] and methyl chloride [134 g (2.66 moles, 4.0 equivalentsrelative to aluminum)], the after-purification yield of trimethylaluminum was 40% (relative to aluminum).

EXAMPLE 7

Using an aluminum-magnesium alloy obtained in the same manner as inComparative Example 1 by spraying a molten aluminum-magnesium alloy in anitrogen atmosphere by the use of a spray dryer, a reaction of the alloywith methyl chloride was conducted in the same manner as in Example 1.

In the above reaction between aluminum-magnesium alloy [45 g (0.677 moleas aluminum)] and methyl chloride [134 g (2.66 moles, 4.0 equivalentsrelative to aluminum)], the after-purification yield of trimethylaluminum was 25% (relative to aluminum).

EFFECTS OF THE INVENTION

The process of the present invention has made it possible to synthesizea trihydrocarbyl aluminum at a high yield from an aluminum-magnesiumalloy and a halogenated hydrocarbon.

As a result, it has become possible to produce, in particular, trimethylaluminum, at a far lower cost than before and in high volume.

What is claimed is:
 1. A process for producing a trihydrocarbylaluminum, comprising the steps of: mixing and melting aluminum andmagnesium to obtain an aluminum-magnesium alloy of 20-80% aluminum and20-80% magnesium; cooling the alloy to solidify the same; grinding thealloy to obtain an alloy powder; reacting the alloy powder with ahalogenated hydrocarbon while agitating the alloy powder and thehalogenated hydrocarbon, to form a trihydrocarbyl aluminum, wherein thealloy powder and the halogenated hydrocarbon are agitated with abrasiveparticles or are treated by a homogenizer without abrasive particles;and recovering the trihydrocarbyl aluminum.
 2. The process according toclaim 1, wherein, in the reaction step, the agitation is conducted at anagitation speed of 50-5,000 r.p.m. or the homogenizer treatment isconducted at a rotation speed of 5,000-20,000 r.p.m.
 3. The processaccording to claim 1, wherein, in the grinding step, the grindingtreatment is conducted with abrasive particles.
 4. The process accordingto claim 1, wherein the halogenated hydrocarbon is methyl halide ormethyl chloride.
 5. In a process for producing a trihydrocarbyl aluminumby reacting an aluminum-magnesium alloy of 20-80% aluminum and 20-80%magnesium with a halogenated hydrocarbon, wherein the improvementcomprises agitating with abrasive particles or treating by a homogenizerwithout abrasive particles the aluminum-magnesium alloy and thehalogenated hydrocarbon during the reaction.
 6. The improvementaccording to claim 5, wherein the agitation is conducted at an agitationspeed of 50-5,000 r.p.m. or the homogenizer treatment is conducted at arotation speed of 5,000-20,000 r.p.m.